Conde Ladie Anne, Kebede Biniam, Leong Sze Ying, Oey Indrawati
Department of Food Science, University of Otago, Dunedin 9054, New Zealand.
Philippine Root Crop Research and Training Center (PhilRootcrops), Visayas State University, Baybay City 6521, Leyte, Philippines.
Foods. 2022 Nov 18;11(22):3714. doi: 10.3390/foods11223714.
The research aimed to investigate the effect of pulsed electric field (PEF) treatment on cassava flour at mild intensities (1, 2, and 4 kV/cm) combined with elevated levels of specific energy input (250−500 kJ/kg). Influences on starch digestibility, morphological characteristics, birefringence, short-range order and thermal properties were evaluated. Application of PEF at energy input no greater than 250 kJ/kg had negligible influence on the different starch digestion fractions of cassava flour but raised the rapidly digestible starch fraction at a combined electric field strength >1 kV/cm and energy input >350 kJ/kg. Morphological evaluation revealed that at this PEF combination, cassava starch’s external structure was consistently altered with swelling and disintegration, albeit some granules remained intact. Consequently, this led to disruption in the internal crystalline structure, supported by progressive loss of birefringence and significantly lower absorbance ratio at 1047/1022 cm−1. These physical and microstructural changes of the inherent starch promoted the shift in gelatinization temperatures to a higher temperature and reduced the gelatinization enthalpy. The study demonstrated that PEF can be utilized to change the starch fraction of cassava flour, which is driven by electric field strength and specific energy input, causing changes in the starch-related properties leading to increased digestibility.
该研究旨在探究温和强度（1、2和4 kV/cm）的脉冲电场（PEF）处理与特定能量输入水平升高（250−500 kJ/kg）相结合对木薯粉的影响。评估了其对淀粉消化率、形态特征、双折射、短程有序性和热性能的影响。在能量输入不超过250 kJ/kg的情况下施加PEF对木薯粉不同淀粉消化部分的影响可忽略不计，但在电场强度>1 kV/cm且能量输入>350 kJ/kg的组合下，快速消化淀粉部分有所增加。形态学评估表明，在这种PEF组合下，木薯淀粉的外部结构持续发生变化，出现膨胀和崩解，尽管仍有一些颗粒保持完整。因此，这导致内部晶体结构受到破坏，表现为双折射逐渐丧失以及在1047/1022 cm−1处的吸光度比显著降低。淀粉固有结构的这些物理和微观结构变化促使糊化温度向更高温度转变，并降低了糊化焓。该研究表明，PEF可用于改变木薯粉的淀粉部分，这受电场强度和特定能量输入驱动，导致淀粉相关性质发生变化，从而提高消化率。
